Managing Referenced Masters
With the release of version 1.5 Aperture moved into a new world of functionality. It also made it disturbingly easy for photographers to misplace images. Sure, Aperture knows where your images are (or are supposed to be) but it doesn't bother to tell you where the master lives.
If you use only managed masters then this article isn't of any use for you.
Since the release of Aperture 1.5 I have used a total of 3 drives for master storage: my MacBook Pro's internal HD (managed and referenced), an external 2.5" FireWire hard drive, and a desktop hard drive. I have since then simplified my workflow and am trying to consolidate my masters. Sure, I could use the Consolidate Masters… command, but I found another method that I like.
Get yer drives
Connect/mount all of the drives that contain your master images. This can be a fun exercise all by itself.
Select your images
I started by selecting all of my images by using the All Images built-in Smart Album and hitting Command-A
Manage Referenced Files…
Choose File > Manage Referenced Files… After Aperture verifies your masters, you will be presented with the following window:
The top left pane will show you the disks that contain the masters for all of the images you've selected. You can select a disk in this pane and Aperture will show you all of the images on that disk. The reason this is cool is that you can now select all of those images and click the mysterious Update Selection In Browser button.
The powerful Update Selection In Browser button
OK, so it isn't that mysterious (it does what it says it does...). Click it and go back to the Aperture browser. Notice how the selection has changed and is now just the images that you had selected in the Referenced Files in Selection window.
You can now do a File > Relocate Masters… and move your masters from one disk to another or to your Library.
Neat, huh?